Syntormon

The genus is diagnosed by the structure of the antennae: the pedicel (second antennal segment) possesses a small thumb-shaped projection extending into the inner side of the postpedicel (first unit of the flagellum), creating a pinned or socketed appearance. This feature is the basis for the genus name derived from Greek 'syntormóō' (I connect by inserted pins). Species-level identification requires examination of male genitalia and other fine morphological details.

Species have been collected in forested environments, particularly in wet biotopes including river basins, lakes, and forest margins. In Inner Mongolia, specimens were collected at Mount Helan, Mount Jiufeng, Xiaojinggou, and Heilihe using sweep nets.

Worldwide distribution with approximately 50+ species described from the Palaearctic realm. Documented from Europe (Denmark, Norway, Sweden), and China (Inner Mongolia, Henan, Shaanxi, Yunnan). The genus is newly recorded from Inner Mongolia.

• SympycnusSyntormon praeteritus was moved to Sympycnus, indicating historical taxonomic confusion between these genera; both belong to subfamily Sympycninae and share general body plan.
• Other Dolichopodidae generaThe distinctive pedicel-postpedicel articulation separates Syntormon from most other dolichopodid genera, which lack this thumb-like projection.

• long-legged flies
• Dolichopodidae
• Palaearctic
• antennal morphology

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Syntormon Loew (Diptera, Dolichopodidae) from Inner Mongolia, China, with the description of a new species.